Die cutter assembly and mounting means for punch thereof

ABSTRACT

A punch member is resiliently mounted in one of two opposed rollers and is captured by structure that permits some radial movement of the punch relative to the roller. One or more dies are secured on the surface of the other of the two cooperating rollers and co-act with the punch to provide a shear cutting operation on a web that is moving between the two rollers. Both the punch and the die are readily removable from their respective roller. Means are also provided for adjusting the magnitude of the resilient force that acts radially on the punch.

United States Patent Wilkins 1451 Apr. 25, 1972 [54] DIE CUTTER ASSEMBLY AND 1,180,102 4/1916 Avery ..s3/34s MOUNTING MEANS FOR PUNCH 1,673,244 6/1928 Hires et al. .....s3/34s x 3,064,513 11/1962 Hershey ..83/348 X Primary Examiner-James M. Meister Attorney-Leonard H. King [57] ABSTRACT A punch member is resiliently mounted in one of two opposed rollers and is captured by structure that permits some radial movement of the punch relative to the roller. One or more dies are secured on the surface of the other of the two cooperating rollers and co-act with the punch to provide a shear cutting operation on a web that is moving between the two rollers. Both the punch and the die are readily removable from their respective roller. Means are also provided for adjusting the magnitude of the resilient force that acts radially on the punch.

10 Claims, 6 Drawing Figures PATENTEDAPR 25 m2 3 6 57, 9 54 7 INVENTOR. 54 I JOHN f. WILKINS v w/ A ATTORNEY DIE CUTTER ASSEMBLY AND MOUNTING MEANS FOR PUNCH THEREOF This invention relates generally to die cutting apparatus and more particularly to improved mounting means for the punch portion of the punch and die set in a rotary cutting device.

BACKGROUND OF THE INVENTION Rotary cutting devices are commonly used for high speed blanking or cutting apparatus such as used for example in making envelopes or the like. A rotary punch and die set is used specifically for forming the windows in envelopes. One example of this type of structure is shown in U.S. Pat. No. 3,106,121 issued on Oct. 8, 1963, to A. Novick. The structure in this patent comprises a pair of spacedly mounted elongated rollers having substantially parallel axis. Oneof the rollers acts as a die and'a rectangular punch is secured to the other roller, the axis of the punch being slightly skewed with respect to the axis of the roller. Of particular importance is the fact that the punch is rigidly secured by means of fasteners to the roller. When the envelope passes between the two rollers a shear cutting action is provided by virtue ofthe skewed punch.

Still another example of a cutting and punching tool for continuous webs is shown in U.S. PatNo. 3,381,560 issued to DB. Mages on May 7, 1968. Once again, the punching tool is rigidly secured to one of two spacedly opposed rollers. Substantially the same general construction is disclosed in U.S. Pat. No. 3,128,663 issued on Apr. 14, 1964, to NE. Dovey. While the cutting knives in this last mentioned patent are rigidly secured to a support member that is rotatable, a mass of relatively non-compressible, flexible material such as rubber, is positioned about the knife blade in order to hold the blade in engagement with the knife support. It should be noted, however, that the knife in the last mentioned patent is prevented. from moving radially with respect to the longitudinal axis of the roller on which it is supported.

By way of contrast, the structure comprising the present invention provides means for resiliently supporting the punch portion of a punch and die set. The punch is mounted on a roller and is resiliently biased by a spring member whose compression rate may be varied by means of a screw that extends through the punchbody and which bears against the spring. The punch, whichhas an enlarged flat formed on one side surface thereof, is captured by means of a screw that is chordally positioned in the roller. The capturing screw engages the elongated flat sothat, within the limits of the flat, the punch is permitted some radial movement by the urging of the compression spring that is positioned between the punch and the roller.

In one embodiment of the present invention, the radially outward surface of the punch is spherical and, in operation, bears against a tubular die that is secured to the opposite roller by means of achordally positioned screw. The radially outward end of the die is positioned tangentally with thesurface of the second roller and, inoperation, the punch did not enter the die but instead rolls along the surface thereof whereby the spherical surface of the punch infcooperation with the inner diameter of the tubular die provides for a shear cutting action. The structure of the present invention just described will act to punch out circular, disc-like portions, from the web passing between the two rollers.

In another embodiment of the present invention, the radially outward surface of the punch is semi-spherical. The punch is shaped such that the spherical portion only contacts the die when the two rollers are rotated. The non-spherical portion of the. punch clears the die and does not contact the mating cutting edge thereof. Thus, the second embodiment of the present invention thus described provides for an arcuate cut in the material passingbetween the two rollers. No material then is actually removed form the web. A hinged tab is formed by the semi-spherical punch. The bend line for the tab is defined by thediameter that divides the spherical portion of the punch from the relieved portion thereof. One application of the secondembodiment of thepresent invention is in the fon'n of a mulching blanket. With a plurality of the arcuate cuts formed in the blanket, as described above, the web may be placed on the ground to cover an area to be seeded. The seeds are planted in the openings and the resultant seedlings can push up through the blanket by bending the tabs formed in the web. However, the remainder of the blanket covers the ground and effectively prevents the growth of weeds or the like.

Accordingly, it is a primary object of the present invention to provide an improved punch and die cutter assembly.

It is another object of this invention to provide an improved mounting structure for a punch member of a punch and die cutter assembly.

A specific object of this invention is to provide means for resiliently mounting the punch member of a punch and die cutter assembly.

An important object of the present invention is to provide structure, as described above, wherein a punch in a punch and die cutter assembly is permitted some limited radial movement with respect to the longitudinal axes of the roller on which it is secured.

An important feature of the present invention is that the radial force acting outwardly on the punch may be readily varied.

A feature of the present invention is that the punches are readily interchangeable.

Another advantage of the present invention is that different punches may be accommodated for either blanking out material or forming a cut of suitable size and shape in the material passing between the two rollers.

These and other objects, features and advantages of theinvention will, in part, be pointedout with particularity and will, in part, become obvious from the following more detailed description of the invention, taken in conjunction with the accompanying drawing, which forms an integral part thereof.

In the various Figures of the Drawing, like reference characters designate like parts.

In the drawing:

FIG. 1 is a schematic elevational view illustrating the environment of the present invention;

FIG. 2 is an enlarged fragmentary elevational view in section illustrating the relationship of the punch and die comprising the present invention;

FIG. 3A is an end view of one embodiment of the punch comprising the present invention;

FIG. 3B is a schematic, perspective view of the cutout formed by the punch shown in FIG. 3A;

FIG. 4A is an end elevational view of an alternative embodiment of the punch comprising the present invention; and

FIG. 4B is a schematic perspective view of the cut provided by the punch shown in FIG. 4A.

Referring now to FIG. 1, there is shown one typical environment of the present invention. The punch and die assembly 10 is fed by an extruder 12 that is arranged to deliver a continuous web of material. A takeup assembly generally designated 14 is positioned downstream of the punch and die assembly and is arranged to receive the material therefrom. While an extruder 12 has been illustrated it should be noted that the material need not necessarily be plastic. Any thin punchable web of material may be utilized by the present invention. For example, a thin continuous web of paper may be punched out in the manner that will now be described.

For understanding the construction of the present invention, reference may be had to FIG. 2. The punch and die assembly is comprised of two spacedly opposed rollers 16 and 18 that have longitudinal axes substantially parallel to each other. A punch 20 is resiliently mounted in the roller 16 in a manner now to be described.

The punch 20 is comprised of a body portion 22 that is substantially cylindrical and which is received in a radial bore 24 formed in the roller 16. The radially outer end 26 acts as the cutting means of the punch 20. A bore 28 formed in the head end of the punch 20 terminates in a transverse radially inward web 30 that is internally tapped in order to receive a screw 32.

At the opposite end the punch 20 is formed with a second coaxial bore 34 that is adapted to receive a compression spring 36. It will be seen in FIG. 2 that the spring 36 acts between the bore 24 in the roller 16 and the transverse web 30 in the punch 20. A washer or disc like member 38 is positioned in the bore 34 at the radially outward end of the compression spring 36 so that axial movement of the screw 32 will cause the spring 36 to be compressed. An elongated axially extending flat 40 is formed on the body portion 22 of the punch 20 and is engaged by a locking screw 42 that extends chordally through the roller 16.

Once the correct compressive force of the spring 36 has been established by means of the axial displacement of the screw 32, the screw 42 is brought into engagement with the flat 40. The screw 42 does not bind against the punch 20 but instead acts to capture it and allow some radial movement of the punch 20 within the limits defined by the ends of the flat 40. Thus the punch is resiliently captured and cannot inadvertently fall out.

The opposed roller 18 is provided with a tubular die 44 that is captured therein by means of a set screw 46 positioned chordally within the roller 18. The die 44 is positioned in a radial bore 48 formed in the roller 18 such that the radially outward end of the die 44 is substantially tangential with the surface of the roller 18. As shown particularly in FIG. 2, the punch 20 does not enter the die 44 in the conventional manner but instead rolls along the transverse outer end thereof. The inner diameter of the die 44 in cooperation with the outer cutting end of the punch 20, form the mating cutting means comprising the present invention. When the web of material M passes between the punch 20 and the die 44, the material M is either punched out or cut as shown in FIGS. 38 and 4B, respectively.

When the head end of the punch 20 is spherical (FIG. 3A), a circular cutout 50 is made in the web of material M as shown in FIG. 3B. An alternative embodiment is shown in FIG. 4A wherein the head end of the punch 20' is a semicircle having a relieved portion 20a. This embodiment of the punch 20 provides for an arcuate cut 52 to be made in the material M. The diametric line 54 running across the cutting end of the punch 20 forms a bend line 56 in the material M as shown in FIG. 4B. It should be clearly understood that the present invention is not limited to either of the two configurations shown in FIGS. 3A and 4A.

From the foregoing, it will be appreciated that an improved punch and die assembly has been described and illustrated. The improved punch and die assembly provides for resilient mounting of the punch portion thereof by means of a compression spring acting radially outward. A fastener captures the punch while permitting limited radial movement of the punch. The material passing between the punch die may either be blanked out or only a partial cut may be formed therein depending upon the shape of the punch itself.

There has been disclosed heretofore the best embodiment of the invention presently contemplated. However, it is to be understood that various changes and modifications may be made by those skilled in the art without departing from the spirit of the invention.

What I claim as new and desire to secure by Letters Patent 15:

l. A cutter assembly for a continuous movable web of material, said cutter assembly comprising the combination of:

a. a pair of spacedly opposed rollers having longitudinal axes that are substantially parallel to each other;

b. a punch having a coaxial bore mounted on one of said rollers and a die mounted on the other of said rollers such that when said rollers are rotated angularly about the longitudinal axes thereof, said punch rollingly engages said die and thereby cuts the web of material passing therebetween;

c. resilient means extending between said punch and said roller, said resilient means exerting a radially outward force on said punch with respect to the longitudinal axes of said one roller, said resilient means comprising a compression spring positioned in the bore of said punch;

d. adjusting means for changing the magnitude of the force exerted by said resilient means; and

e. means for capturing said punch on said one roller.

2. The cutter assembly in accordance with claim 1 wherein said adjustment means is a screw threaded into said punch and acting coaxially on said spring.

3. A cutter assembly for a continuous movable web of material, said cutter assembly comprising the combination of:

a. a pair of spacedly opposed rollers having longitudinal axes that are substantially parallel to each other;

b. a punch mounted on one of said rollers and a die mounted on the other of said rollers such that when said rollers are rotated angularly about the longitudinal axes thereof, said punch rollingly engages said die and thereby cuts the web of material passing therebetween;

c. resilient means extending between said punch and said roller, said resilient means exerting a radially outward force on said punch with respect to the longitudinal axes of said one roller;

d. adjusting means for changing the magnitude of the force exerted by said resilient means; and means for capturing said punch on said one roller comprising a recess formed on the outer surface of said punch, said recess having axially spaced end walls and wherein there is further provided a screw threaded into said roller and arranged to engage said recess, the spaced end walls of said recess defining means for limiting the radial movement of said punch in cooperation with said screw.

4. A cutter assembly for a continuous movable web of material, said cutter assembly comprising the combination of:

a. a pair of spacedly opposed rollers having longitudinal axes that are substantially parallel to each other;

b. a punch mounted on one of said rollers and a die mounted on the other of said rollers such that when said rollers are rotated angularly about the longitudinal axes thereof, said punch rollingly engages said die and thereby cuts the web of material passing therebetween, said die being a tubular member secured in the other of said roller in coaxially spaced opposition to said punch and said punch having a head end that includes a first portion arranged to coact with said tubular die member and thereby provide a cut in the material passing therebetween, said punch further including a second portion at the head end thereof, said second portion being spaced from said die and out of engagement therewith when said rollers are rotated whereby the material passing between said second portion and said die is not cut;

. resilient means extending between said punch and said roller, said resilient means exerting a radially outward force on said punch with respect to the longitudinal axes of said one roller;

d. adjusting means for changing the magnitude of the force exerted by said resilient means; and

e. means for capturing said punch on said one roller.

5. The cutter assembly in accordance with claim 4 wherein said first portion of said punch is spherical.

6. An improved punch for a rotary cutting device having two opposed rollers between which the material to be cut is passed, said punch being mounted on one of the rollers and arranged to cooperate with a die mounted on the other roller, said punch comprising:

a. a body portion having first and second coaxial bores therein and an internally threaded transverse wall separating said bores;

b. a compression spring mounted in one of said bores for resiliently biasing said punch with respect to the roller in which it is mounted; and

c. a screw threaded into the transverse wall and acting on said spring for changing the magnitude of the force exerted by said spring.

7. The improved punch in accordance with claim 6 further including means for capturing said punch while permitting radial movement thereof with respect to the longitudinal axes of the roller.

8. The improved punch in accordance with claim 7 wherein said capturing means is defined by a recess formed on the outer surface of the body portion of said punch and a screw chordally mounted in the roller in which said punch is disposed, said screw being in engagement with said recess, said recess having axially spaced end walls defining the limits 

1. A cutter assembly for a continuous movable web of material, said cutter assembly comprising the combination of: a. a pair of spacedly opposed rollers having longitudinal axes that are substantially parallel to each other; b. a punch having a coaxial bore mounted on one of said rollers and a die mounted on the other of said rollers such that when said rollers are rotated angularly about the longitudinal axes thereof, said punch rollingly engages said die and thereby cuts the web of material passing therebetween; c. resilient means extending between said punch and said roller, said resilient means exerting a radially outward force on said punch with respect to the longitudinal axes of said one roller, said resilient means comprising a compression spring positioned in the bore of said punch; d. adjusting means for changing the magnitude of the force exerted by said resilient means; and e. means for capturing said punch on said one roller.
 2. The cutter assembly in accordance with claim 1 wherein said adjustment means is a screw threaded into said punch and acting coaxially on said spring.
 3. A cutter assembly for a continuous movable web of material, said cutter assembly comprising the combination of: a. a pair of spacedly opposed rollers having longitudinal axes that are substantially parallel to each other; b. a punch mounted on one of said rollers and a die mounted on the other of said rollers such that when said rollers are rotated angularly about the longitudinal axes thereof, said punch rollingly engages said die and thereby cuts the web of material passing therebetween; c. resilient means extending between said punch and said roller, said resilient means exerting a radially outward force on said punch with respect to the longitudinal axes of said one roller; d. adjusting means for changing the magnitude of the force exerted by said resilient means; and e. means for capturing said punch on said one roller comprising a recess formed on the outer surface of said punch, said recess having axially spaced end walls and wherein there is further provided a screw threaded into said roller and arranged to engage said recess, the spaced end walls of said recess defining means for limiting the radial movement of said punch in cooperation with said screw.
 4. A cutter assembly for a continuous movable web of material, said cutter assembly comprising the combination of: a. a pair of spacedly opposed rollers having longitudinal axes that are substantially parallel to each other; b. a punch mounted on one of said rollers and a die mounted on the other of said rollers such that when said rollers are rotated angularly about the longitudinal axes thereof, said punch rollingly engages said die and thereby cuts the web of material passing therebetween, said die being a tubular member secured in the other of said roller in coaxially spaced opposition to said punch and said punch having a head end that includes a first portion arranged to coact with said tubular die member and thereby provide a cut in the material passing therebetween, said punch further including a second portion at the head end thereof, said second portion being spaced from said die and out of engagement therewith when said rOllers are rotated whereby the material passing between said second portion and said die is not cut; c. resilient means extending between said punch and said roller, said resilient means exerting a radially outward force on said punch with respect to the longitudinal axes of said one roller; d. adjusting means for changing the magnitude of the force exerted by said resilient means; and e. means for capturing said punch on said one roller.
 5. The cutter assembly in accordance with claim 4 wherein said first portion of said punch is spherical.
 6. An improved punch for a rotary cutting device having two opposed rollers between which the material to be cut is passed, said punch being mounted on one of the rollers and arranged to cooperate with a die mounted on the other roller, said punch comprising: a. a body portion having first and second coaxial bores therein and an internally threaded transverse wall separating said bores; b. a compression spring mounted in one of said bores for resiliently biasing said punch with respect to the roller in which it is mounted; and c. a screw threaded into the transverse wall and acting on said spring for changing the magnitude of the force exerted by said spring.
 7. The improved punch in accordance with claim 6 further including means for capturing said punch while permitting radial movement thereof with respect to the longitudinal axes of the roller.
 8. The improved punch in accordance with claim 7 wherein said capturing means is defined by a recess formed on the outer surface of the body portion of said punch and a screw chordally mounted in the roller in which said punch is disposed, said screw being in engagement with said recess, said recess having axially spaced end walls defining the limits of radial movement of said punch
 9. The improved punch in accordance with claim 6 wherein the cutting portion of said punch is defined by a spherical head.
 10. The improved punch in accordance with claim 6 wherein the cutting portion is defined by a head having a first section that is spherical and a second portion that will be spaced from and out of engagement with the die when said first portion contacts the die. 